Identification of herbal tea ingredient Mesona chinensis and its adulterants using ITS2 barcode / 中国药学杂志

ABSTRACT

OBJECTIVE: To establish an accurate and rapid method for identifying Mesona chinensis and its adulterants using the internal transcribed spacer 2 (ITS2) region as a barcode. METHODS: The total genomic DNA from 55 samples representing five species and four variants including M. chinensis and its adulterants were extracted. The ITS2 regions were amplified, and the complete ITS2 sequences were annotated by CodonCode Aligner. The intra- and inter-specific genetic distances based on Kimura 2-Parameter (K2P) and the Neighbor-Joining (NJ) phylogenetic tree were analyzed to identify the species. RESULTS: The lengths of all the 1TS2 sequences of M. chinensis were 232 bp. The intra-specific genetic distances (0) were far shorter than the inter-specific ones between M. chinensis and its adulterants (0.210 2-0.301 9). NJ tree analysis indicated that M. chinensis were accurately differentiated from its adulterants. CONCLUSION: The ITS2 region as an DNA barcode can accurately and effectively distinguish herbal tea ingredient M. chinensis from its adulterants, which provides a quick identifying method to ensure its safe use.